This method mainly focuses on the analysis of Y and mitochondrial DNA, but besides these there are many more chromosomes. Such heritage is cultural and historical, but how can it give an adequate answer about biological inheritance? Why aren't the rest of the chromosomes being studied?

2 hours ago, molbol2000 said:

Such heritage is cultural and historical, but how can it give an adequate answer about biological inheritance?

Let me reverse the question, why do you think that those markers are inadequate? You'll have to be more precise as there are different tools for different purposes. 

 

11 hours ago, CharonY said:

Let me reverse the question, why do you think that those markers are inadequate? You'll have to be more precise as there are different tools for different purposes

For example, they ignore maternal grandfather. 
There is no complete picture of inheritance

If we ask what is the origin on the maternal and paternal side, then it's ok. But if we ask what is the origin in general, what peoples influenced heredity besides straight lines, that's wrong.

I think for adequate picture must be sequensed all chromosomes and find all markers